The present invention relates to an improved brake construction for a cloth-laying machine.
By way of background, cloth-laying machines are commonly used whenever layers of cloth have to be deposited on a table for subsequent cutting. These machines carry a roll of cloth which, when full, may weigh anywhere between 500 and 1,000 pounds, and the roll may be unwound at a linear speed of up to 300 feet per minute. However, depending on conditions which the machine is experiencing, such as slowdown or reversal, the roll must be braked in order to match its linear unwinding speed to the speed of the machine on the table. In the past various types of brakes have been used, none of which could provide the necessary braking to the cloth roll. In this respect, one type of prior brake comprised a disc brake secured to the mandrel on which the roll was mounted. This brake was deficient for two reasons. Firstly, it operated close to the center of the cloth roll and therefore did not have a sufficiently large lever arm to produce effective braking. Secondly, the roll of cloth could continue to rotate after braking, considering that the only connection between the cardboard roll on which the roll was wound and the mandrel was through a series of teeth. Whenever there was slippage between the teeth and the cardboard roll, the latter would get ruined and even possibly the cloth could get torn. If there was no slippage between the teeth and the cardboard roll, there was still the possibility that the roll of cloth would not stop unwinding if it was not securely fastened to the cardboard roll, which was a common occurrence. Another type of brake arrangement used with cloth-laying machines was the type associated with braked rollers on which the outer periphery of the cloth roll rested. However, this type of braking was also deficient in that there was only line contact between the cloth roll and the supporting rollers therefor. This line contact, in addition to not providing a large braking surface, also caused undesirable indentations on the roll of cloth. In addition to the foregoing, it was known to lay a web across the roll of cloth with one end of the web anchored to the frame and the other end carrying a weight. This was deficient because it could not apply acute braking as needed.